1. Field of the Invention
This invention relates to tanks for containing large volumes of fluids, and more particularly, to tanks adapted to contain fracturing fluids of high density, and frequently of a corrosive character.
2. Brief Description of the Prior Art
In my U.S. Pat. No. Des. 253,051, I illustrate a tank adapted for the containment of fluids used in fracturing subterranean formations to stimulate the production of oil and gas therefrom. Such tanks are generally rested upon the ground at a drilling or oil production site, and serve as a reservoir for containing acid or various chemical compositions used for fracturing or increasing the permeability of a hydrocarbon-containing formation. They are then cleaned and transported to a new fracturing site. To facilitate transport, such tanks have a step at one end to accommodate a dual-wheeled truck or dolly, and provided with a fifth wheel-engaging structure at the opposite end. In order to provide maximum fluid capacity without sacrifice of transport capability, such tanks are often of trapezoidal configuration as shown in may above-cited design patent.
The fluids which are used in well treating and in formation fracturing and which are often placed in such tanks are frequently corrosive to metal, and are sometimes quite dense. When the latter characteristic is experienced, the fluid tanks used to contain such fluid must be structurally strong to avoid bulging or mechanical failure. The tank illustrated in my U.S. Pat. No. Des. 253,051 is well adapted for the containment of dense and corrosive liquids. It includes a V-shaped bottom having a trough extending longitudinally of the bottom along the center line thereof which facilitates the emptying of the tank, and the washing down and cleaning of the tank after its usage at a job site is completed.